Dishwashing machine



Nov. 20, 1962 J. DJWARHUS I DISHWASHING MACHINE Filed Sept. 20. 1957 Hll' a Sheets-Sheet 1 INVENTOR. JOH N D. WARHUS lam/4M ATTORNEY Nov. 20,1962 Filed Sept. 20, 1957 J. D. WARHUS DISHWASHING MACHINE 6Sheets-Sheet 2 INVENTOR. JOHN D. WARHUS MA JAMAQ/ ATTORN EY Nov. 20,1962 J. D. wARHu's 3,064,654

DISHWASHING MACHINE Filed Sept. 20, 1957 6 Sheets-Sheet 3 INVENTOR. JOHND. WARHUS ATTORNEY Nov. 20, 1962 J. D. WARHUS ,664

DISHWASHING MACHINE Filed Sept. 20, 1957 e Sheets-Sheet 4 i i 51 x} 8 K4 I 42 42 Z; m u 20 43 20 I A 2 I I mm INVENTOR. m I 39 JOHN D. WARHUSBY q 39 Wk M I 3 ATTORNEY Nov. 20, 1962 J. D. WARHUS DISHWASHING MACHINEFiled Sept. 20, 1957 6 Sheets-Sheet 5 JOHN D. WARHUS Q iMA/W ATTORNEYPatented Nov. 29, 3852 lid 3.064.664 DIHWAHING MACHINE John D. Warhus,Lombard, 11]., assignor to General Electric Company. a corporation ofNew York Filed Sent. 20, 1957. Ser. No. 685,303 7 Claims. (Cl. 134-176)This invention relates to domestic appliances, such as dishwashingmachines.

The modern automatic dishwasher'used domestically, as distinguished fromthe specialized apparatus used in restaurants and other large-scaleeating establishments, is subject to being rather haphazardly loaded bythe user, and because the washing of the dishes within the dishwashertub is effected by the impingement of multitudes of droplets of washingliquid against the dishes. it will be seen that the loading arrangementof the dishes has much to do with the effectiveness of the washingaction. It will also be obvious that because the manner in which thedishwasher is loaded and used may vary from day to day, or even frommeal to meal, the washing etl'lciency may vary over a rather wide range;

The majority of domestic dishwashers presently use either an impeller ora reaction spray device in the lower 13ft of thetub-and thus depend onupwardly directed water sprays to wash the miscellany of dishes andother articles placed in open-work racl sor a spray device disposedintermediate the upper and lower racks and designed to obtain a suitablewater distribution pattern.

The disadvantage of the first-named arrangement is that itsefiectiveness is particularly subject to the manner of loading and typeof dishes; whereas in dishwashers embodying the second circulationarrangement, bowls, cups, and glasses must be arranged in invertedfashion in the upper rack. This, it is not always possible'to do.

It has previously been proposed to employ a reaction spray device belowthe lower rack, and a second one intermediate the upper and lower racks.This arrangement is productive or a good water distribution pattern, butthe necessary pipe connections have been costly and bulky, and theintermediate reaction spray device has on occasion damaged dishes bystriking them during rotation. The reaction spray devices of the priorart have usually comprise a twoor three-armed device mounted for freerotation in a horizontal plane, and havingvariously disposed nozzleseffective when liquid under pressure is supplied thereto, to rotate thedevice and provide a wide coverage and e;re..tive contact of the washingand rinsing liquids with tie dishes and other articles placed in therack immediately thereabove.

It is an object of the present invention to provide a dishwasher usingupper and lower spray nozzle devices, arranged to produce optimumwashing action without possibility of damage to the dishes within thetub.

It is another object of the invention to provide an upper spray nozzledevice which is fixed relative to one of the racks for an efficientspray pattern relative to the dishes in the washing chamber or tub, andautomatically becomes physically detached from its liquid supply meanswhen said supply means is shut oil, thereby permitting said rack to bereely moved relative to the tub to facilitate loading or unloading therack.

It is a further object of the invention to provide a novel means forautomatically coupling and uncoupling the upper and lower spray nozzledevices of a dishwasher.

It is still another object of the invention to provide improved meansfor rotatably mounting'a spray nozzle device in proper position within adishwasher tub.

' In a presently preferred embodiment of the invention, a dishwasher tubis provided with a bottom hinged door, movable between a substantiallyvertical closed position and a substantially horizontal open position.An upper and a lower dish-receiving rack are supported within said tubin a manner permitting them to be with; drawn through the door openingto facilitate leading, us is well known in the art. A liquiddistribution such as a reaction-type spray nozzle device is rot-stablymounted beneath the lower rack for rotation in a horizontal plane, andmotor-driven pump means is provided for drawing the washing liquid froma low point within the tub and discharging it at relatively high pressure into the liquid distributor, from the radially extending arms ofwhich it issues in variously disposed sprays and jets reflective toimpinge against the articles in the racks immediately above and thuswash them. Certain of the jets are arranged to produce a rotation of thedistributor as long as the liquid is supplied thereto at necessarypressure.

The lower rack rotatably supports a vertical, rigid water supply conduithaving a bell-ed, open end, disposed, when the rack is in operativeposition, immediately above an upwardly facing discharge port in the hubportion of the liquid distributor. Said conduit terminates intermediatethe upper and lower rack, and at its upper end carries a second spraynozzle liquid distribution device having discharge ports which directstreams of liquid in various patterns against the articles located inthe upper and lower racks. Said second distributor may or may not havereaction jets to impart a rotative efiort thereto, because pursuant to apreferred form or" the invention rotative effort is applied thereto bythe lower distributor. to the lower rack engage with a fitting at thetop of the upper liquid distributor.

An important aspect of the invention is that means are provided forautomatically coupling the conduit to the lower liquid distributor whenthe lower rack is in operative position and liquid under pressure isdelivered to said lower distributor. By means of this coupling, liquidunder substantial pressure is supplied to the conduit and thence to theupper distributor when the dishwasher is in any of its water-usingcycles, such as the washing or rinsing cycles. At the end of suchcycles, the conduit is automatically uncoupled from the lower liquiddistributor, making it possible to withdraw and return the lower rackwithout conflict with the lower distributor. In a presently preferredembodiment, I utilize an annular expansion coupling fixed about theaxial discharge opening provided by the open upper end of the hubportion of the lower liquid distributor. Said coupling has an inwardlyextending flexible lip which defines a discharge port of substantiallyless area than the said axial opening in the distributor. When the lowerrack is in home position, the 'belled end of the conduit is disposedimmediately above but in spaced relation to the discharge port of thecoupling. When liquid under pressure enters the coupling from the lowerliquid distributor, the pressure exerted against the underside of thelip causes the coupling to move upwardly into sealing relation with theconduit and liquid under substantial pressure is thereby delivered 'bythe conduit to the upper water distributor. So positive is theengagement of the lip of the coupling with the conduit that the conduitand its associated upper distributor is actually lifted relative to thelower rack, and is rotatively driven by the lower distributor.

Another feature of the invention resides in the fact that the upperliquid distributor comprises a flat disklike structure of plasticmaterial. The rounded peripheral edge of the upper distributor and theinherently resilient nature of the material substantially eliminates thepossibility of damage to articles which Bearing means suitably supportedrelative through careless loading of the racks may rest against or bestruck by the rotating disk.

Although the dishwasher embodying the present invention may be arrangedfor gravity drainage, I prefer to use a drain pump to insure fast andcomplete removal of the dishwasher liquids. The drain pump inlet is disposed substantially centrally of the screen, and thus is in a positionefficiently to accumulate and discharge the food soil which has gatheredin the sump.

Other features and advantages of the invention will be apparent from thefollowing description of a presently preferred embodiment, read inconnection with the accompanying drawings in which:

, FIG. 1 is a side sectional elevation of a dishwashing machine, takenon lines I i of FIG. 3, with the filter structure removed, the loadingdoor partly open, and the lower rack partially projecting through theopening;

FIG. 2 is a front sectional elevational view of the dishwasher with thefront door removed and the lower front panel partially broken away todisclose structural details and accessories normally concealed thereby;

FIG. 3 is a plan section of the dishwasher tub looking in the directionof the arrows 33 of FIG. 2, but with the filter structure removed;

FIG. 4 is a fragmentary sectional elevation taken on lines 4-4 of FIG.3;

FIG. 5 is a sectional elevation taken on lines 55 of FIG. 3 showing therelationship of the filter screen to the drain pump inlet;

FIG. 6 is a fragmentary sectional elevation of the hub portion of thelower liquid distributor and the lower portion of the upper distributorconduit, with the flexible coupling in relaxed condition;

FIG. 7 is a view similar to FIG. 6, showing the flexible coupling inextended condition;

FIG. 8 is a plan view of the upper liquid distributor;

FIG. 9 is an upper sectional elevation of the upper distributor andconduit; and

FIG. 10 comprises a schematic wiring diagram and cam sequence chart. IReferring initially to FIG. 1, the dishwasher 1 embodying the presentinvention comprises a washing chamber or tub 2 suitably housed within astructural casing 3. The tub has a front opening fitted with a bottomhinged door 4 which is shown in a partially open position. The door isarranged to operate between a substantially vertical closed position anda substantially horizontal open position. The door, or the tub margin,as desired, is ordinarily fitted with a suitable gasket (not shown) forsealing the tub when the door is in its closed position. The side wallsof the tub are provided with a pair of upper tracks 5 and a pair oflower tracks 6 which respectively support the upper dish rack structure7 and the lower dish rack structure 8. For example, the respective racksare suitably provided with rollers which engage with the tracks, topermit the upper and lower racks to be withdrawn through the frontopening of the tub to facilitate loading the racks with the dishes andother articles (not shown) to be washed. Preferably, means is providedto prevent the complete withdrawal of the upper rack 7. The lower rack 8substantially completely occupies the lower portion of the tub when itis in operative position, but may be withdrawn completely from the tub,in view of the fact that in such a circumstance it will be supported bythe horizontal inner panel of the door 4 when the later is in itsfullopen position. The upper and lower racks are of openworkconstruction and include various formed-wire supporting structures,pursuant to which cups, glasses, saucers, and other small articles maybe suitably arranged in the upper rack, and dishes, platters, bowls, andthe like may be placed in the lower rack. A silverware basket (notshown) is normally removably associated with the lower rack for articlesof tableware.

The bottom of the tub 2 slopes to a sump portion,

which, as shown in FIG. 2, is somewhat to the right of the tub whenviewed from the front. A solenoid-operated valve 9 connected by way of apipe 10 to a source of heated water (not shown) is provided forsupplying the tub with heated water. The valve discharge tube 11 extendsvertically between the tub and the outer casing 3, and the water issuingtherefrom passes through a vertical air gap of not less than one inchinto a pipe 12 which communicates with the interior of the tub. Apressure switch 14- (FIGS. 1 and 3) having a diaphragm 15 exposed withinthe tub is responsive to the head of water within the tub; and ifbecause of some faulty operation of the machine a quantity of wateraccumulates within the tub, the switch 14 will operate to open the valvecircuit, thus preventing overfilling. The dishwasher apparatus isarranged to be fully automatic in its operation and a conventionaltime-cycle controller 16 is suitably disposed within the dishwasherdoor. The timecycle switch is provided with a control knob 17 on theoutside of the door, and, as will more fully appear hereinafter, thetime-cycle switch will conduct the dishwasher operation through apredetermined cycle of washing and rinsing operations. The inside panelof the door carries a device for the introduction of detergent into thewater so as to produce a suitable washing liquid. The detergentintroduction device 18 is desirably of the type in which fresh detergentis mixed with water in each of two washing operations, as shown anddescribed inv the Sharp et al. Re. 24,198, entitled DishwashingApparatus with Automatic Detergent-Dispensing Means, and assigned to mypresent assignee. A heating unit 19 of the tubular sheathed resistncetype is mounted within the tub to facilitate the drying operation. Inthe present embodiment of the dishwasher, two gallons of water are usedin each of the washing and rinsing operations, but this relativelysmallquantity is circulated at the rate of thirty gallons per minute. At notime, therefore, is there any substantial depth of liquid within thetub. For the washing operations, the water mixes with detergent toprovide the washing liquid. Rinsing is carried out by clean hot water,although in the final rinse a water conditioner, such as a wettingagent, may be added.

The washing and rinsing of the articles contained in the respectiveracks 7 and 8 is accomplished by means of sprays of liquid forcefullyejected from a pair of rotating spray devices which efficientlydistribute the liquid throughout the tub. The lower liquid distributorcomprises a reaction spray device rotatably mounted below the lower rack8, whereas the upper distributor comprises a different form of spraynozzle device which is rotatably mounted between the upper and the lowerracks. The lower distributor 29 is illustrated as a twoarmed deviceprovided with a plurality of upwardly facing slots 21 which spray thewashing or rinsing liquid against the articles in the lower rack, andwith opposingly directed openings 22 which provide reaction forces whichcause the lower distributor to rotate. This action literally drenchesthe dishes and other articles which are racked in the lower portion ofthe tub. The upper water distributor 23 comprises a relatively flat,hollow disk-like structure which is advantageously molded ofthermosetting plastic, such as Bakelite. The rounded periphery of theupper distributor and the complete absence of any sharp edges orprojections makes it impossible to damage dishes which may accidentallycome into contact with it. The upper distributor is provided withsuitable ports 24, 25, 26, 27, and 28, later described in detail, whichproduce water streams which extend in a generally outward and upwarddirection.

During the washing and rinsing operations, the upper and lowerdistributors are continuously supplied with liquid at a pressure whichat admission to the lower distributor is about eleven pounds per squareinch gage. This is provided by a centrifugal pump 3% disposed in a. com

par cent below the tub, and driven by an electric motor 31. The pumpinlet 32 communicates with a tube 33 formed in the combined watercirculation and drain fitting 34, best shown in PEG. 4. The inlet tosaid tube 33 comprises a cylindrical collar or baffle 35 which projectsupwardly into the tub for about one-half inch and receives a portion ofthe filter structure 36, as presently described.

The pump outlet 37 communicates directly with a support and supplyconduit 38 for the lower distributor. Advantageously, the connectionbetween the pump outlet 37 and the conduit 38 comprises a combinationgasket and sleeve 39, best shown in FIG. 6. The pump outlet 37 fitswithin the sleeve 39 which, as shown in FIG. 6, has an outwardlyextending flange 39a, which receives the bottom of the tub 2 andsupports the flanged base 38a of the conduit 33. Any suitable means,such as the illustrated fastening devices, may be used to maintain therespective parts in a suitable water-tight relationship.

The conduit 38 is provided with an interior spider 40 which carries anelongated pivot bearing 41 arranged'coaxially with the conduit 38.Bearing 41 rotatably receives a socket 42 which is preferably anintegral part of the hub 43 of the lower distributor 20. A tubularextension 47 of said hub is outwardly flared to receive the base 44 ofthe flexible coupling member 45. it will be observed from FIG. 6 thatthe axial opening 46 in said coupling member is considerably smallerthan the axial opening 47 of the hub i3, whereupon when liquid isflowing through said extension under pressure from the pump 3%, thecoupling will be displaced in an axial direction. Preferably, theflexible coupling is of a synthetic rubber-like material, such asneoprene, which is resistant to the detergents used in present-daydishwashers. In a present embodiment of the invention, the pump pressurewithin the hub 43 of the lower distributor 20 is of the order of elevenpounds per square inch, and said pressure is distributed over aboutthree square inches of the end of the coupling 45, whereupon there is aneffective force of about thirty-three pounds applied against the insideof the coupling to upwardly expand the same.

As more specifically disclosed in the presently pending application ofThomas P. Zurek, Serial Number 685,447, filed September 23, 1957, fordishwashing apparatus and assigned to my assignee herein, it has beenfound possible to eliminate rotating seals and the like at the juncturebetween the conduit 38' and the hub 43 by beveling' the lower edge ofsaid hub so that the wall of the hub ext ads into a very close, butnevertheless finite clearance, forms a very sharp angle with the insidewall. The hub re ionship with the upper fiat wall of the conduit 38, andit will be noted from FIG. 6 that the inside diameter of the hub 43 isslightly larger than the inside diameter of the conduit, whereupon theknife edge 48 of the hub 43 is intermediate the inner and outer walls ofthe conduit 33. There is, of course, a very small escape of liquidthrough the clearance space between the hub and the fitting. Any smallfood soil particles which may haveescape the screen will not lodge inthe clearance space because of the escape facilities provided by thebeveled edge It has previously been noted that the upper liquiddistributor 23 is supported by the lower rack 8. As shown in FlGS. 1 and6, the support includes the metal conduit 5% which has about its lowerportion a hub 51 which may be of nylon or the like. The lower portion ofthe nylon hub is beveled, as at 52, to pilot into a ring-like support 53which is formed in the bottom of the rack 8. It will be noted from P16.6, that the inner wall of the hub 51 is grooved; the outer wall of theconduit 59. is knurled, as at 54, to provide an interlockingrelationship with one of the internal grooves of the hub. The conduit 5ienters the hub 55 of the upper distributor 23 to supply water to saiddistributor, as later described. Additional support for the upperdistributor is provided by the bearing 56 which is disposed at theextremity of the support frame 57 fixed to and extending upwardly from.the lower rack 8.

The lower end of the conduit 50 is provided with a bell-like mouth atwhich is disposed immediately above the upper flexible end of theexpansion coupling 45. The hub 51 maintains a concentric relationshipbetween the conduit 50 and the lower distributor hub 43 when the lowerrack 8 is in its operative position. The relationship of the lower rackto the inner panel of the door 4 is such that the rack 8, if slightlyout of position as the door is closed, will be engaged by the door paneland moved to its operative position. As appears in FIG. 7, when themachine is in operation and water under pressure is issuing through thehub 43 of the lower distributor, the expansion of the flexible coupling45 brings it into positive engagement with the lower surface of the bell60 and actually lifts the upper distributor assembly relative to thelower rack 8. Thehub 51 at'the lower end of the conduit 56 is then in adefinite clearance relationship with the portion 53 of the lower rack.This of course reduces the friction of the'upper distributorrotatingsystem, a nd although the upper distributor. may be formed to havereaction jets, it is primarily rotated by means of the firm pressureengagement between the coupling member 45 and the bell 60.

As best shown in FIGS. 8 and 9, the upper liquid distributor 23 isarranged so that in spite of its small diameter as respects the lowerdistributor, it provides avery efiicient liquid distribution pattern.The outside diameter of the upper distributor 23 is, in the presentcommercial embodiment of this invention, six inches, as compared withthe eighteen inch arm spread of the lower distributor 20. The upperdistributor 23 is provided with tWoarrangemerits of marginal slots whichare characterizedby different extents of fan-Wise discharge. Forexample, the slots 24 are arranged (FIG. 8) so that the fan-likedischarge therefrom makes an angle of approximately fifty degreesrelative to the horizontal, whereas the slots 25 are formed so that thedischarge makes an angle of approximately thirty-five degrees from thehorizontal. There are, in addition, angularly inclined circular ports26' which are disposed at substantially the horizontal center line ofthe distributor. The ports 26 may, if desired; be arranged to producereaction jets for the rotation of distributor 23.

The top of the distributor is similarly provided with two arrangementsof water ejection slots. A central group of slots, identified as 27,projects directly upwardly. It will be noted from MG. 8 that none ofthis group ofslots is at the same radius from the axis of rotation ofthe distributor. The second group of slots 2-8 is sufficiently close tothe upper marginal edge of the distributor to permit a slight outwardincline. The resulting action is essentially to discharge liquid underpressure in an outward direction from the slots 24, 25, and 26; in adirectly upward direction from the slots 27; and in a substantiallyupward but somewhat outward direction from-the slots 28.

It will be observed from FIG. 9 that the upper distriow tor is atwo-part device in which the hub 55 has a portion which is in a keyedrelationship to the upper end of the conduit 51} and is fixed thereto byset screws 62 or equivalent. The upper portion of distributor 23 isprovided with a central hub 63 which provides means for mounting theupper needle bearing member 64 which upon an extreme upward displacementof the conduit 5%, as aforesaid, may rotatably seat within the conicalbase of the- These walls are adaptedto enter the collar 35- so asfrictionally to engage the inside wall thereof. The engagement of thewalls within the collar 35 stabilizes the filter relative to the drainfitting and, together with the short leg portions 71 (of which there aretwo at the front of the filter and rest upon the bottom wall of the tub2), securely supports the filter structure relative to the tub bottom. Afixed handle 73 facilitates the insertion and removal of the filter. Aboss 74 is arranged to receive the screw 75 which forms the primarymeans for securing the filter screen 76 in position. As is evident froma comparison of FIGS. 4 and 5, the screen 76 is a generally concavestructure, the upper edge of which engages the rim or shoulder 69 withinthe filter cover 66. The projected area of the screen 76 issubstantially less than that of the cover 66.

The drainage fitting 34 has a relatively deep sump '77 which drainstoward the outlet 78. A drainage pump conduit 80 issuitably securedabout the outlet 78 and communicates directly with the drainage pump 81which is driven by an electric motor 82. The discharge 33 from the pump81 rises to a point substantially above the bottom of the tub fordischarge-through an air break (not shown) of at least one inchinto theplumbing waste line (not shown) of the building. A coarse guard plate 84prevents passage of material which might clog the discharge pump.

The element 70 extends through a suitable aperture in the screen, andwhen the filter structure is in operative position, a portion of thescreen immediately circumscribing the aperture rests upon the upper edgeof the collar 35. When the pump 3!) begins operation for a wash or rinseportion of the operational cycle, the liquid level in the sump is belowthe rim 67 of the filter cover 66. The liquid can flow to the pump 30only by passing upwardly through the filter screen 76 and then throughthe passages provided by the walls of the element 70 into the pump inletconnection 32. Heavy food soil will accumulate in the sump 77 and willenter the drain pump inlet pipe 80; the lighter soil will be interceptedon the outside of the screen 76 and thus prevented from passing into thewater distributor system. Any small particles of soil which maypenetrate the screen 76 will be carried into the inlet 32 by flow alongthe passages provided by the walls of the element 70. The pumping rateof thirty gallons per minute floods the interior of the filterstructure, and because the operation of the pump 30 is abruptlyterminated at the end of the washing or rinsing operation, the liquidwithin the filter will backfiow through the screen and remove the foodsoil therefrom.

An important aspect of the filter design is that when the pump 36 is inoperation, there is a slight negative pressure existing Within thefilter structure, and the atmospheric pressure within the tub exertedover the relatively larger area of the imperforate cover 66 tends tohold the filter structure firmly against the thrust exerted by theupward flow of liquid through the screen.

FIG. comprises a composite figure showing the cam sequence chart and aschematic wiring diagram for a control system useful with a dishwasherembodying the present invention. The sequence timer 16 includes asynchronous motor 85 which may be of the well-known Telechron type. Saidmotor operates through a speed reduction and friction clutch mechanism86 to drive a cam shaft on which are mounted six cams, designated 37 to92 inclusive. The knob 17 on the cam shaft provides for manual rotationof the cams to place the cams in a home position, advance the operationto any desired cycle, or to shorten a particular operation. The frictionclutch permits such manual operation, as is well understood in the art.

Cam 87 controls the operation of the drain pump motor 82; cam 88, theheating element 19; cam 89, the circulation pump motor 31; and cam 90,the solenoid coil of the water valve 9. Cam 9]. is the so-called shortcycle cam which comes into operation when the user wishes to operate thedishwasher for an abbreviated cycle, as presently explained, and cam92.jis a bypass cam which maintains the timer motor in operation at orthe line 93 switch has been automatically opened by operation of thetimer. With respect to this latter feature, it may be noted that theparticular form of timer used by my assignee herein is of a conventionaland commercially well-known type in which the cam shaft is manuallymovable in an out' ward axial direction, and in its outwardly movedposition closes the line switch 93; and when the timer has rotated thecam shaft through the major part of its operational cycle, the cam shaftis automatically returned to a home position in which the line switch 93is opened. A door switch 94 is of a conventional, normally open type; itis operated to closed circuit position when the dishwasher door isclosed, and assumes its open position whenever upper edge of the door ismoved as little as one-eighth of an inch away from fully closedposition. A beneficial effect of such an arrangement is that if the dooris open sufficiently to permit the rack 8 to be displaced relative tothe lower distributor 26, the dishwasher is inoperative.

Assuming now that the machine has been loaded with dishes and thatdetergent has been placed in each of the cups of the detergent dispenser13 and the dispenser placed in its operating position, as is fullydescribed in the said Sharp et al. Reissue Patent 24,198, the user thendetermines whether the machine is to operate through its normal washing,rinsing, and drying cycle, or whether it is to operate on theabbreviated cycle. According to her decision, she operate the pushbuttonswitch 95; and assuming that she has decided on the full cycle, heroperation of the switch will close the contacts thereof and therebyshunt-out the switch 91a which is associated with the short cycle cam91. When the door is closed (which closes witch 94), the user pullsoutwardly on the control knob 17, thus closing line switch 93 andenergizing the electrical system.

The timer motor begins operation immediately. Switch a in the watervalve circuit is in closed circuit condition at this stage of operation,and so, of course, is the water switch 14, for there is no water in thetub.

Cam 87 is holding switch 87a closed at this time, and

the drain pump motor 82 is therefore operating. The result is that forthe first sixty seconds, water is flowing into the tub through the inletpipe 12 and is passing directly to the drain pump 82 for discharge. Thepurpose of this is to purge the valve inlet pipe 10 of the cool waterwhich it may then contain. After sixty seconds, the drainage operationterminates; and in view of the fact that circulation pump 30 is inoperation, water issues forcefully from the distributors 20 and 23.During the first portion of this operation, the water washes thedetergent out of one of the cups of the detergent dispenser 18,whereupon a washing solution is created. During this operation, also,the detergent dispenser prepares itself for supplying detergent to thenext washing operation.

At the end of four minutes, cam 87 again closes its drain pump switch87a for one minute, whereupon the washing liquid is discharged. Thecirculation pump remains in operation in order to purge the pump casingand associated conduits of most of the spent washing liquid. After theone minute discharge operation, cam 89 closes 7 its switch for anotherone-minute fill, and there ensues a apogee;

9.. switch 89a also opens, signifying the end of the washing and'rinsingphases of the operational cycle.

As indicated in the cam sequence chart, when the circulation and drainpumps finally terminate their operation-which would be at the end of thenineteenth minute of operationthe cam 38 closes its switch 88a toenergize the heater 19. The heater l9 maintains an elevated temperaturein the tub to facilitate the air-drying of the dishes and other articlestherein. At about the forty-first minute of operation, the timer beginsthe line switch kickout operation. The kick-out impulse-that is to say,the movement of the line switch to open circuit position actually occursin the forty-fourth minute. In the meantime, however, cam 92 has closedits switch 92a providing a bypass around the line switch 93; and whensaid line switch opens, it is without effect as respects the continuedoperation of the timer motor 85. Said motor remains in operation untilthe fiftieth minute has passed, at which time the cam 92 has openedswitch $201, and thereby has restored the sequence timer to a conditionwhich makes it ready for the next operation of the dishwasher.

The presently commercial embodiment of the dishwasher uses two gallonsof water for each of the washing and rinsing operations. The valve 9 isof the well-known type having a flow control device, pursuant to whichit delivers two gallons per minute over a range of inlet water pressurefrom about fifteen pounds per square inch to more than seventy-fivepounds per square inch, thus accommodating itself to the range of waterpressures found in the average domestic installation. During the firstminute of operation, two gallons of water will, therefore, have beendischarged by the pump 81; and during the second minute another twogallons will be delivered to the tub andwill be available for the firstwashing operation. It the drain valve discharge were plugged up, or, iffor some reason the pump 80 did not operate during the first minute, theaccumulation of two gallons of water during the first minute wouldoperate the switch 14 to open circuit position and no more water couldbe admitted to the tub. Switch 14 is, therefore, a safety switch toprevent flooding the dishwasher.

As is evident'from the cam sequence portion of FIG. 10, the short cyclecam 91 maintains the line circuit closed for a period which includes twowashing and one rinsing operation. This operational cycle is useful, forexample, in washing pots and cooking ware, as its primary function'is toloosen and remove stubborn soil and place the pots in condition for afinal cleaning by hand or by a later operation of the normal dishwashingcycle. It will be noted that when the short cycle cam opens its switch91a, all power is interrupted, for the preliminary preparation for theshort cycle operation includes operating the switch 95 to open circuitcondition. At the end of the short cycle of operation, therefore, thetimer has not reached the condition where it has reset itself for reuse.It is necessary for the operator by manipulation of the timer controlknob 17 to restore the timer to its home position, in which therespective cam actuated switches, including the switch 91a, are preparedfor the next operation.

While there has been described what is at present con sidered to be thepreferred embodiment of the invention, it will be understood thatvarious modifications may be made therein, and it is intended to coverin the appended claims all such modifications as fall within the scopeof the invention.

I claim:

1. In dishwashing apparatus including a tub having an opening in a walland a door for said opening and means for supplying said tub with aquantity of washing liquid: a rack to accommodate articles to be washed;means for mounting said rack for movement to or from an operatingposition in said tub; a first spray nozzle device extending laterally ofsaid rack in parallel spaced relation thereto,

said device having a multiplicity of openings for discharging liquidagainst articles in said rack; a conduit; means for mounting said spraynozzle device on one end of said conduit in communication therewith;means for mounting said conduit on said rack, the opposite end of saidconduit being open and below said rack; a second spray nozzle device,comprising an open ended tubular huh and spray arm means extendinglaterally therefrom; means for rotatably mounting said second device insaid tub below said rack with the hub coaxial with said conduit whensaid rack is in its operating position, an open end of said hub openlyfacing said conduit open end in spaced relation therewith, said hub openend being substantially larger in diameter than that of said conduit; anannular resilient coupling member disposed on said hub open end andhaving an annular wall portion radially inward ofthe hub wall fordisplacement into mechanical engagement with said conduit end underinfluence of liquid pressure within said hub, the opening in saidcoupling member being substantially equal to the conduit diameter forsubstantially unrestricted flow of liquid from said hub portion intosaid conduit; means for supplying liquid from said tub to said hub underpressure sufficient to, effect said coupling displacement and in volumeto supply both said spray nozzle devices for discharge of liquidtherefrom; and means for effecting rotation of said last named spraynozzle device relative to said rack while maintaining said couplingmembers in engagement with said conduit.

2. Dishwashing apparatus, comprising a tub; means for supplying washingliquid thereto; means including a rack for accommodating articles to bewashed; means for removably supporting said rack in an operatingposition within said tub; a first spray nozzle device, said deviceincluding an u anding hub providing an axial discharge opening facing llbottom of said rack; means for mounting said spray nozzle device forrotation about the axis or" its hub; a second spray nozzle device; arigid openended conduit fixed at one end to said second spray nozzledevice to provide for fiow of washing liquid directly thereinto, saidsecond spray nozzle device extending laterally therelrom for asubstantial distance and having a multiplicity of openings fordischarging liquid against said rack; bearing means interposed betweensaid rack and said second spray nozzle device at the aids of rotation offor supporting said conduit for rotation relative to said rack whilepermitting axial displacement of said conduit and associated secondspray nozzle device; hub means on said conduit engageable with said rackto position the f ee end of said conduit below said rack in apredetermined vertically spaced axial alignment with the axial dischargeopening or" said first spray nozzle device, the hub means on saidconduit being arranged to disengage from said rack upon axialdisplacement of said conduit; a resilient coupling fixed to the hub ofsaid first spray nozzle device concentrically about the axial openingthereof, said coupling having structure assuming an inactive positiondisengaged from the open end of said conduit out displaceable intomechanical engagement therewith to provide an enclosed flow passagebetween the hub of said first spray nozzle device and said conduit undera condition of positive liquid pressure within said first spray nozzledevice; pump means for supplying liquid from said tub to said firstspray nozzle device at the said positive pressure condition; thedisplacement of said coupling into mechanical engagement with saidconduit effecting the disengagement of said conduit hub means from saidrack, whereby said conduit is supported by said coupling and saidbearing means; and means for rotating said first spray nozzle devicerelative to said rack.

3. Dishwashing apparatus, comprising structure providing a tub having awall opening; a closure door therefor; means for supplying said tub withwashing liquid; a dishraclt in the lower portion of said tub, a dishrackin the upper portion of said tub; means for positioning said upper andlower racks in vertically spaced operative position while permitting atleast the lower rack to be drawn through the tub wall opening; a firstspray nozzle device having a tubular hub and at least one spray armmember extending laterally therefrom, means for mounting said spraynozzle device below said lower rack for rotation about the axis of saidhub portion; means including reaction-spray means on said arm member forrotating said hub; means comprising an open-ended tubular extension ofsaid hub for discharging liquid axially upwardly therefrom; a conduithaving an open end; means for rotatively mounting said conduit on saidlower rack with the said open end coaxial with said hub extension and invertically spaced relation therewith when said lower rack is inoperative position; a resilient annular coupling member fixed to thesaid hub extension for displacement into mechanical engagement with saidconduit about the open end thereof under influence of liquid pressurewithin said hub, the opening of said annular member being smaller thanthe discharge diameter of said tubular extension and coaxial therewith;a second spray nozzle device, said device having a multiplicity ofindividual openings disposed in a common plane for discharge of liquidtoward said upper rack; means for mounting said second devicenonrotatably on said conduit intermediate said upper and lower racks,said second spray nozzle. extending laterally from said conduit incommunication therewith; and means for pumping liquid from said tub intosaid hub and tubular extension thereof under sufiicient pressure toengage said coupling member with said conduit end and in sufficientvolume to supply both of said spray nozzle devices; said coupling memberproviding a driving connection between said hub and said conduit forrotating said conduit conjointly with the first spray nozzle device.

4. In dishwashing apparatus including a tub having an opening in a walland a door for said opening and means for supplying said tub with aquantity of washing liquid: a rack to accommodate articles to be washed;means for mounting said rack for movement to and from an operativeposition in said tub; a first spray nozzle device; a con duit; means forsecuring said device to one end of said conduit for receipt of liquidtherefrom, said spray nozzle device extending laterally from saidconduit for a substantial distance parallel to the horizontal plane ofsaid rack to discharge liquid against articles therein; means forsupporting said conduit on said rack, the other end of said conduitbeing open and adjacent the base of said rack; a second spray nozzledevice, comprising an open-ended tubular hub and spray arm meansextending laterally therefrom; means for mounting said second device insaid tub with the hub coaxial with said conduit when said rack is in itsoperative position, an open end of said hub openly facing said conduitopen end in spaced relation therewith, said hub open end beingsubstantially larger in diameter than the open end of said conduit; anannular resilient coupling member disposed on said hub open end fordisplacement into a substantially liquid tight mechanical engagementwith said conduit end under influence of liquid pressure within saidhub, the opening in said coupling member being smaller than the hub openend to provide a substantial area of said coupling member subject toliquid pressure; means for supplying liquid to said hub under pressuresuincient to effect said coupling displacement and in volume to supplyboth said spray nozzle devices for discharge of liquid therefrom intosaid tub; and means for effecting rotation of said second spray nozzledevice relative to said rack while said coupling member remains insubstantially liquid tight engagement with said conduit.

5. Dishwashing apparatus, comprising structure providing an open-fronttub having a door swingable between open and closed positions relativeto said tub front opening, open-work racks for dishes disposedrespectively within the lower portion and the upper portion of said tuband arranged for individual movement through said tub opening to or froman operative position in said tub, a

reaction spray device rotatably mounted in said tub below said lowerrack, means for supplying said device with a continuous supply of liquidunder pressure to rotate said device and effect the discharge of spraysof liquid throughout said tub, said reaction spray device having anupstanding hub portion provided with an axial discharge opening facingsaid lower rack, a rigid, open ended conduit supported in said lowerrack for free rotation relative thereto, a spray nozzle device fixed toand extending laterally from an end of said conduit below said upperrack for rotation by said conduit in a plane parallel to the base ofsaid rack, said spray nozzle device having individual discharge openingsdisposed at various radial distances from the axis of rotation thereofto discharge liquid against articles in said upper rack, said conduitproviding means for supplying said spray nozzle device with liquid andhaving its open end disposed, when said lower rack is in operatingposition within said tub, in vertically spaced axial alignment with theaxial discharge opening of said reaction spray device, coupling meansfixed on said hub portion about said axial opening in normal verticallyspaced relation to the open end or" said conduit, means responsive tothe flow of liquid through with hub to displace said coupling means tosealingly engage with said conduit about the open end thereof, wherebyduring operation of said dishwashing apparatus said conduit and said hubportion form a unitary, rotating, conduit through which liquid issupplied to said spray nozzle device and said conduit is physicallydisconnected from said reaction spray device when liquid flow throughthe said hub portion is discontinued, thus under the last-namedcircumstance permitting the lower rack to be withdrawn from said tubwithout conflicting with said reaction spray device. 7

6. Dishwashing apparatus, comprising a tub adapted to hold a quantity ofdishes and other articles to be washed, a rack for containing saidarticles, means for mounting said rack for removal from an operatingposition in said tub, a first spray nozzle device having dischargeopenings directed toward said rack, means fixed relative to said tub formounting said device for rotation in a plane be low and parallel to saidrack, means including an upstanding, open-ended hub portion forsupplying said spray nozzle device with liquid under pressure todischarge liquid against articles in said rack, means for effectingrotation of said spray nozzle device during discharge of liquidtherefrom, a second spray nozzle device, means carried by said rack formounting said second device for axial movement relative to said rack androtation in a plane above and parallel to said rack, said second spraynozzle device including means providing a water passage extending forseveral inches laterally of the axis of rotation thereof and havingapertures for discharging individual streams of liquid against articlesin said rack from different radial distances from said axis of rotation,said mounting means positioning said second device in a predeterminedvertically spaced position relative to said first spray nozzle devicewhen the rack is in operative position within said tub, and means fixedto the hub portion of said first spray nozzle device and responsive tothe issuance of liquid therefrom to mechanically couple said hub portionto said second spray nozzle device for rotation therewith and to supplysaid second spray nozzle device with liquid under pressure for dischargethrough the apertures thereof.

7. Dishwashing apparatus, comprising a tub, upper and lower openworkracks disposed in vertically spaced relation within said tub to containarticles to be washed, means for mounting at least said lower rack forremoval from an operating position in said tub, a spray nozzle devicedisposed within said tub for rotation in a horizontal plane intermediatesaid racks, said device comprising a fiat, disk-like, structure having amultiplicity of discharge openings disposed throughout a surface of saidstructure facing said upper rack to direct sprays of liquid towardarticles therein, a rigid open-ended tube rotatably mounted in saidlower rack, means for aflixing said spray nozzle device to one end ofsaid tube to receive liquid therefrom, means including an upwardlyextending conduit disposed Within said tub below said lower rack, saidconduit having an open end facing said rack in axial alignment with thebottom of said tube, means for supplying said conduit with a flow ofliquid under pressure, means responsive solely to the discharge ofliquid from the said open end of said conduit to mechanically connectsaid tube to said conduit end for establishing a pressure-tight flowpassage between said conduit and said tube, and means for effecting therotation of said tube and spray nozzle device during flow of liquidunder pressure thereinto.

References Cited in the file of this patent UNITED STATES PATENTS2,063,746 Meeker Dec. 8, 1936 Donnelly Mar. 14, 1950 De Lisle May 16,1950 Marmo et al. July 5, 1950 Sway Jan. 5, 1954 Lengrenis June 7, 1955Stanitz et a1 Aug. 16, 1955 Oxford Dec. 13, 1955 James Jan. 17, 1956Federighi Apr. 3, 1956 Sisson June 5, 1956 Low June 26, 1956 Clark July3, 1956 Low Nov. 27, 1956 Bradley et al. Feb. 26, 1957 Low Mar. 4, 1958Ullman et a1 June 23, 1959 FOREIGN PATENTS Austria Feb. 10, 1953

